Furnace for desulfurizing and agglomerating ores.



4No. 875,331. PAT'ENTED DBO. s1, 19o?. A. BULL @L J.- WEATHERBY, JR.

FURNAGE FOR DESULFURIZING AND AGGLOMERATING DRES.

APPLICATION FILED PBB.4.1907.

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uuuuguuu Vea No. 875,331. PATENTED DEC.31, 1907. A. J. DULL & J. WEATHERBY, JR.

FURNACE PGR DESULFURIZING ANDYAGGLOMERATING ORBS'.

= APPLICATION FILED FEB. 4. 1907.

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TIE- E UNITED sTATEs PATENT oEEioE.l

ANDREW J. DULL, OF HARRISBURG, AND JOSEPH WEAITHRBY, JR., OF NEW GUMBERLAND,

PENNSYLVANIA; SAID WEATHERBY ASSIGNOR TQ SAID DULL. y

FURNAGE FOR DES`U'I.E"URIZING` AND AGGLOMERATING CRES..

Specification of Letters Patent.

Patented .'Dec. 31., 1907.

Application led February 4 1907. Serial No. 355.6191

To all whom 'it' may concern.'

Beit known that we, Aivnnnw J. DULL, a citi-zen of the United States, residing at Han risburg, in 'the county of Dauphin, State of Pennsylvania, andJosErir WEATHERBY, Jr., a citizen of the United States, residing at New Cumberland, in the county of Cumbei land and State of Pennsylvania, have invented certainnew and useful VIm rovenients in Furnaces for Desulfurizing and Agglomerating Gres; and we do declare the following to be a full, clear, and exact descri tion of the invention, such as will enablev ot l1ers skilled in the art to which it appertains to make and 'use the saine. y

`Our invention relates toimprovements in furnaces for d esulfurizing and aggloinerating coniminuted iron ore I,to convert the same into a cinder, which may be subsequently treated in a blast furnace, and it consists in an ore roasting furnce having means to pro.u duce an electric arc, and means to eX ose the ore, after the saine has been heate in the furnace, to the action of such electric arc.

Our invention further consists in an ore roasting furnace ha means to produce an electrica arc, and means to cause the ore, after the same has been in a heated condition and While it is heated, to pass between the electrodes of the arc for agglomeration thereby.

Our invention further consists inan cre roasting furnace having a moving element to set up motion in the ore heated in the furnace, and means to roduce an electric arc, to the action of whichJ the heated moving ore is exposed feragglonieration thereby.

Our invention further consists in an ore roasting furnace having a moving element to tween the" electrodes in the arc, and remove said agglomerated mass from the sphere of action of the arc.

Our invention further consists in the con.

struction, combination and arrangeinentof devices hereinafter described and. claimed.

linthe accompanying drawings,-Figure l is a sectional view of one ty e 0fa roasting furnace for desulfurizing an agglomerating iron ore, and embodying' our improvements;

Fig. 2 is a detail sectional view illustrating v the construction of one of the electrodes; Fig; 3 is a detail top plan view of the same; Fig. i is a similar view showing a slightly different forni of electrode; Fig. 5 is a sectional 355692 filed by us under date of Feb. 4, 1907.

Referring to the Yform of our invention, shown in Fig.- 1, the furnace` shown therein is iii its general construction an ore roaster of the stirrer type, in which the ore, after it has been ground or coinminuted, is fed by means ofthehopper c, pan f, and chute g onto the uppermost of a series of roasting oors a.v

The ore on the said floors while heated andbeing heated in the furnace is thoroughly stirred and is causedto move by the action of the stirring-arms c, revolved by the shaft b in the furnace, said stirring-arms having teeth d, which in addition to stirring the ore on the floors whiletlie major portion of the sulfur is being burned out therefrom., cause the ore to pass downwardly from Hoor to floor of the furnace and to be finally discharged frorn the furnace through the drawoif pipe h. The products of combustion es cape from the furnace through the exit pipe t in the roof thereof.

l ln the embodiment of our invention we provide one or more electrodes 1, which are,

- hence the teethfclof the stirring-arms re-j` volved by the saidl shaftr become electrodes.

These electrodesI are connectedby view ofanother type of furnace, embodying-L which move over the electrodes 1 ata suit- I able distance therefrom. The interior of the furnace is heated by the usual means and in the usual manner, and combustion therein is maintained in the usual way, the heat being of such a degree as is sufficient to consume the major portion of thesulfur, but is insufficient to fuse the ore. Owing to the stirring action of the stirring-arms and fingers over the floors of the furnace, and the descent of the ore from Afloor to iioor of the furnace, the major portion of the sulfur is removed from the ore before the ore reaches the floor or iioors upon Which the electrode or electrodes l is er are placed. The ore being thus heated inthe furnace, its electrical resistance becomes greatly reduced, as we have discovered in the operation of our improved process. Owing to the reduced resistance of the ore, electric arcs are formed between the electrodes of the movable rakes or arms and the xed electrodes 1, by a current or currents of high amperage but moderate voltage, passing through the ore and the ore while in this heated conditionand in motion in the furnace is subjected to the action of such arcs, the heat of which is superadded to the heat caused by the combustion in the furnace, and the said arcs serve to still further reduce the percentage of sulfur in the ore and to partially fuse the ore, so that the same becomes agglomerated or formed into cinders, which are usually hollow, vary in size from about that of a pea to about that of an egg, and which are of sufficient weight to be adapted to be finally treated in a blast furnace without danger of being blown out of the blast furnace by the force of the blast. Owing to the fact that each arc has an electrode which is movable in respect to and which moves past the other, the cinder or agglomerated mass of ore formed between two such electrodes becomes broken therefrom by the movement of the movable electrode, so that such cinder or agglomerated mass immediately after it has been formed is taken out of the sphere of action of the arc, and a portion of the ore is only momentarily exposed to the action of the electric arc. The ore thus cindered or agglomerated becomes discharged from the furnace through the draw-off pipe h. In practice, We have made the electrodes 1 of cast iron, of circular and segmental form, have embedded the same in asbestos, as at 4, and have further insulated the same by means of fire-brick 5, in which the asbestos has been embedded, so that only the upper surfaces of the electrodes 1 are exposed.

Referring to the modified construction.

shown in Fig. 5, the same in its general construction is substantially like an ordinary revolving cement furnace, in which the metallic -cylinder is supported in an inclined position,

'nace an and is revolved by means of gears n, o. The ore is fed into, the upper end of the furnace, as at p, and a jet of ame is supplied to the interior of the furnace throu h its lower end by a blast pipe r. In this rnace we provide an electrode 6, which is in the form of an iron ring placed in the furnace and insulated from the metallic cylinder c by fire-brick m. At a suitable distance in advance of the annular electrode 6 and spaced therefrom, we provide a number of electrodes 7, which roject through and are insulated from the s ell of the furnace, as at 8. One pole of the generator, indica/ted at 9, is connected to the annular electrode 6. The other pole thereof is connected by a conductor 10 to a contact device 11 with which the electrodes 7 successively make slidin contact as the furnace cylinder, which is t e moving element of the furnace that imparts motion to the ore therein, revolves, so that an arc is established Vbetween each electrode 7 as it reaches the lower side of the furnace and the electrode 6, and

hence the ore as it passes downwardly through the revolving furnace cylinder is exposed to the action of the electric arcs thus successively produced, and is agglomerated or cindered thereb as in the form of'our invention shown in Fig. 1.

From the fore oin'g description, taken in connection with t e accompanyin drawings, the construction and operation o the invention will be readily understood without requiring a more extended ex lanation.

Various changes in the crm, proportion and the minor details of construction may be resorted to without departingl from the principle or sacrificing an of the advantages of this invention, as del claims.

Having thus described our invention, what ed by the appended We claim as new and desire to secure by Letters-Patent, is,-

1. An ore roasting furnace havingA means for heating the ore to desulfurize the same, an electrode arranged in the furnace, a second movable electrode coperating with the firstmentioned electrode to produce an electric arc to the action of which theheated ore is subjected, said movable electrode being adapted to move the agglomerated ore beyond the radius of action of the arc.

2. An ore roasting furnace having means for heating the ore to partially desulfurize the same, a air of electrodes arranged in the furd movable one relative'to the other, means coperating with the electrodes to produce an electric arc to the action of which the heated ore is subjected', and further dsulfurized, one of the electrodes being in the form of a separator for agitating the ore and for removing a glomerated ore out of the radius of action o the arc.

3. An ore roasting furnace havingmeans for heating theoze' a moving element to set oui` hands in presence of tWo subscribing Witu'p motion in the ore heated in the furnace,` nesses. electrodes, and means coecting therewith to produce an electric arc, to the action of ANDREW J. DULL.

5 Whichthe heated ore is exposed, one of said JOSEPH VEATHERBY JR' electrodes being movable with reference to Witnesses: the other, for the purpose set forth. EDWARD M; WINTERS,

In testimony whereof We have hereunto set l JOS. F. WEAVER. 

